The invention relates to a cargo loading system for loading and unloading a cargo deck and a method for creating and/or updating a loading plan.
For transporting air cargo, the cargo items to be transported, in particular containers or pallets, which are preferably fabricated in accordance with specific standards, are fixed inside the cargo hold by means of locking elements on the cargo deck of said cargo hold. Such locking elements frequently form cargo loading paths between which the standardised cargo items can be positioned. Cargo loading systems which assist the ground staff during loading and unloading are used to position the cargo items in the positions intended for them. The cargo loading systems are intended to speed up the process and preferably be very easy to operate as the ground staff have frequently not been given any instruction with regard to a specific cargo loading system. In addition, both loading and unloading is carried out under severe time pressure which can easily lead to incorrect operation.
There is a growing trend for operating companies to want to know where a particular cargo item is located at any one time. On one hand, this information is requested by customers and, on the other hand, such information enables better evaluation of the processes.
Furthermore, it is frequently the case that cargo items are unloaded at the wrong airport or are loaded onto the wrong aircraft.
A poor loading strategy can significantly disrupt operations even when a cargo item is loaded onto the right aircraft. For example, if an aircraft lands at several airports, it is desirable for the cargo items that are to be unloaded at the first destination airport to be located in appropriate positions close to the cargo hatches. Completely unloading the cargo deck simply for the sake of a single wrongly positioned cargo item costs both time and money. Hence there are loading plans which indicate the desired position of a cargo item on the cargo deck. Often, however, these loading plans are not complied with as it is not possible to predict various parameters (weight, number of cases per cargo item, etc.) accurately enough in advance. There are also deviations from the cargo loading plans created in advance because the current situation requires it (for example, a projecting length, a faulty section of the cargo deck, etc.). In these circumstances, it is desirable to be able to carry out a quick update of a loading plan. An appropriate process should preferably be carried out automatically.
Based upon this prior art, it is an object of the present invention to provide an improved cargo loading system which guarantees efficient loading and unloading of a cargo deck. In particular, it should be possible to determine the current position of a cargo item on the aircraft deck of the cargo loading system using the simplest components possible.
The said object is achieved by a cargo loading system according to claim 1.
In particular, the object is achieved by a cargo loading system for loading and unloading a cargo deck, in particular an aircraft deck, wherein the cargo loading system comprises:                at least one cargo reading device mounted in the entrance area of the aircraft, in particular an RFID reading device, for detecting at least one identifier of a cargo item;        a plurality of freight conveying devices each having at least one roller for conveying the cargo item along a conveying route into an end position,        a control system which receives signals from sensors in order to detect a movement of the cargo item along the conveying route and which is communicatively connected to the cargo reading device,wherein the control system is designed to detect the end position of the cargo item on the cargo deck based on the signals and to store data which indicate said end position in conjunction with the detected identifier of the cargo item.        
A basic idea of the teaching according to the invention consists, therefore, of identifying a particular cargo item at a central point, for example near the cargo hatch or the entrance area, and then of tracking the conveying route of the cargo item on the aircraft deck. The conveying route makes it possible to assign an end position to the identified cargo item. According to the invention, this end position should be stored in conjunction with the detected identifier.
A conveying route may be a continuous line, from a starting point up to an end point, of the end position. Due to the mechanical conditions (for example, a cargo deck only has two conveyor tracks), the level of detail of a conveying route can also be selected relatively roughly. Thus the conveying route may indicate the path of the cargo item in sections, for example only at specific branching points.
Moreover, it is not necessary to store the entire conveying route if one can indicate at any time where a specific cargo item is located. In this respect, various transit stops can be taken into account, wherein an assignment between identifier and position is possible at any time. In this respect, a conveying route may also indicate only the path from one transit stop to the next.
The design concept according to the invention makes it possible, without providing a plurality of cargo reading devices which are scattered over the entire aircraft deck, to determine the position of a specific cargo item relatively accurately. The corresponding cargo deck can thus be designed relatively easily. It is possible to dispense with expensive reading devices which can interfere with each other as their number increases.
The control system may be communicatively connected, in particular via a communication bus, to the plurality of freight conveying devices in order to detect activation of at least some of the freight conveying devices and/or to bring this about. Likewise, the communication bus may also connect individual sensors to the control system.
The control system may be implemented centrally or locally.
In one embodiment, the cargo loading system according to the invention exclusively detects the activation states of the freight conveying devices. By tracking these activation states over time, it is possible to determine the conveying route which a specific cargo item takes. Additionally or alternatively, the control system may specify the activation of the freight conveying devices such that the conveying route is actively determined and not merely passively detected.
The accuracy of determining the conveying route is improved if the dimensions of the cargo item are known. The control system may be designed to detect a dimension of a base area of the cargo item and to process it for determining the end position and/or conveying route of the cargo item. In one embodiment, the dimensions are measured in the entrance area of the aircraft by an appropriate sensor system, for example a light barrier. In an alternative embodiment, the detected identifier makes it possible to determine the dimensions of the base area. The cargo loading system may have appropriate tables. Alternatively, a portion of the identifier may specify the base area and/or the type of cargo item. According to the invention it would also be possible to enter the dimensions of the base area manually.
The sensors may comprise light sensors which are arranged and formed on the cargo deck in such a manner that they detect at least the presence of a cargo item. Light sensors on the cargo deck make it relatively easy to detect overlapping of the relevant light sensor by a cargo item. In this respect, it is relatively easy to determine the position of the cargo item at a specific point in time with such sensors.
In one embodiment, the conveying route of a cargo item is determined taking into account sensor signals and signals which indicate the activation state of the freight conveying devices. In this way, a very precise conveying route can be calculated.
At least one subset of the sensors may be arranged in a grid spanning the width of the cargo deck, preferably in the loading and unloading area of said cargo deck. As cargo items are normally rotated in the loading and unloading area and aligned corresponding to the cargo loading path provided, it is advantageous to have a relatively high sensor density in the region of the loading and unloading area. Furthermore, the individual cargo loading paths should be provided with appropriate sensors at least in sections. In a preferred embodiment, sensors for detecting the presence of the cargo item are arranged at least every two meters in the longitudinal direction of a cargo loading path. These sensors are communicatively connected to the control system in order to detect the conveying route of each cargo item.
At least one subset of the freight conveying devices may comprise at least one sensor in each case, preferably two or four sensors, for detecting the cargo item. In one embodiment, these sensors are arranged on the relevant freight conveying device. The sensors preferably surround a roller. Corresponding arrangements are known and are used, inter alia, to raise the roller of a specific freight conveying device at the right time without it being damaged. In state-of-the-art cargo loading systems, alignment of the roller can also take place in advance based on the sensor signals received.
At least one subset of the freight conveying devices should be arranged according to the invention in a grid. This is particularly advantageous in the loading and unloading area of the cargo deck as cargo items frequently pass by here and change their conveying direction as required.
The control system can be designed to store at least some of the signals as a signal set, in particular in conjunction with a sequence and/or a time indication. Basically, it is sufficient to store the identifier of a cargo item in conjunction with the end position. In a preferred embodiment, details are also stored which make it possible to reconstruct the conveying route from the time at which the identifier of the cargo item was detected through to the end position. Corresponding data can be stored in the form of a signal set. In one embodiment, the plurality of detected signals is stored in a sequence so that there is an order which makes it possible to reconstruct the chronological sequence of receiving the signals. Alternatively or additionally, specific time indications can be stored in conjunction with the signals or signal sets. This information is preferably stored long-term so that it is still available even at a later stage.
The control system may be designed to develop a control strategy, taking into account an entered loading position, and to control a plurality of the freight conveying devices according to said control strategy. As already explained, the control system need not be designed merely to detect a control strategy specified by a person such that it is ultimately possible to determine the end position. Cargo loading systems according to the invention may at least automate the loading process such that the loading staff merely have to specify an end position, wherein the control system determines a control strategy such that the cargo items approach this end position. According to the invention, the control system then monitors the loading process in such a precise manner that the conveying route of the cargo item is detected and it can be ascertained with certainty that a specific end position has been approached. In particular, subsequent manual corrections and/or later transshipment operations are detected, wherein the system knows the exact position of a specific cargo item at any time.
The control system may also be designed to monitor the conveying route of a transshipment operation of a cargo item, to determine a new end position of the cargo item taking into account the conveying route, and to store the new end position in conjunction with a detected identifier of the cargo deck. The control system according to the invention thus ensures that the end position assigned to a specific cargo item or to a specific identifier is always up to date.
In addition, the object referred to at the outset is achieved by an aircraft comprising the cargo loading system already described. Similar advantages emerge, such as have already been described in connection with the cargo loading system.
In addition, the object according to the invention is achieved by means of a method for creating and/or updating a loading plan, comprising the following steps:                Detecting an identifier of a cargo item in at least one entry or entrance area of a cargo deck;        Receiving a plurality of signals from sensors which are distributed over at least one section of a cargo deck;        Determining a conveying route based on the signals;        Calculating an end position of the cargo item, taking into account the conveying route;        Storing of data which indicate the end position, in conjunction with the detected identifier.        
In one embodiment, the method is implemented by the cargo loading system already described in one of the configurations described.
Thus, on the method side, a loading plan is created and/or updated, wherein in turn an identifier is detected in a central region, for example in the entrance area of the cargo deck, and then an end position is determined based on tracking of a conveying route. The data pair (identifier and end position) can then be used to update the loading plan, which may already be present, and/or to supplement it. No manual interaction is necessary. Finally, a specified loading plan can also be compared with a loading plan created dynamically on the basis of the method described. Deviations can be detected and displayed for a user. In this way, errors during loading and/or unloading of the cargo deck can be identified and corrected at an early stage.
Detection of the identifier may comprise reading of a memory mounted on the cargo item, in particular of an RFID chip. Identification of cargo items using RFID chips is relatively easy and inexpensive.
Moreover, it is possible when using this technology to dispense with the provision of energy sources on the cargo items such that there is no need for maintenance on the cargo item.
At least some of the signals from the sensors may be stored in a time sequence and/or in conjunction with time indications.
At least some of the signals may indicate an activation of an actuator, in particular of a freight conveying device, at a specific time.
The said object is additionally achieved by means of a computer-readable medium having instructions for performing the method already described, in particular in a specific embodiment, if the instructions are executed on a central processing unit.
Further advantageous developments emerge from the dependent claims.